1. Field of the Invention
The present invention is related to a method for driving a display panel, and particularly to a driving method for solving the problem of the cross talk effect of a display panel.
2. Description of Related Art
FIG. 1 is a structure diagram of a conventional liquid crystal display (LCD) panel. Referring to FIG. 1, a conventional display panel 100 includes a lower substrate 102 and an upper substrate 104. On a surface of the lower substrate 102 facing the upper substrate 104, a plurality of data lines such as D1, D2, D3 and D4 and a plurality of scan lines such as S1 and S2 are disposed and interlaced with each other. Furthermore, on a surface of the upper substrate 104 facing the lower substrate 102, a plurality of color filters 110 is disposed. A common electrode 112 is formed on the color filter 110. In addition, a liquid crystal material is filled between the lower substrate 102 and the upper substrate 104. Therefore, a capacitor exists between the data lines D1-D4 and the common electrode 112.
FIG. 2A is a waveform diagram of data signals and a common voltage of a conventional LCD panel. Referring to both FIGS. 1 and 2A, data signals DS1, DS2, DS3, and DS4 may be transmitted to the data lines D1, D2, D3 and D4 in the display panel 100 respectively. In FIG. 2A, r1 is defined as a bright state voltage, and r2 is defined as a dark state voltage. When one of the scan lines is enabled, the data signals DS1, DS2, DS3 and DS4 may drive each pixel enabled by the scan line.
In some conventional technology, a technique of partitioning time is provided, i.e. partitioning a frame time into at least two sub-frame times. Each of the sub-frame times displays one sub-grayscale. Thus, an image displayed by the display panel within one frame time is constituted by at least two sub-grayscales. Regarding this time-partitioning technique, the conventional technology provides a method of double data rate (DDR) for driving the display panel, as illustrated in FIG. 2B. Referring to FIG. 2B, in this conventional driving technique, a different voltage may be applied to each pixel in different images according to different γ voltage set values to solve the problem of color washout.
Since the liquid crystal capacitance exists in each pixel and in the conventional art the voltage and the polarity transmitted to one pixel are different from those transmitted to another pixel, the coupling effect between adjacent pixels would occur and common voltages Vcom in different areas on the display panel 100 may thus vary. Therefore, most conventional technologies for driving the LCD panel (including DDR driving technique) would cause uneven luminance on the display panel, as illustrated in FIG. 2C. In FIG. 2C, different display areas A1, A2, and A3 have different luminance, which is called the cross talk effect.